THE LUMINOSITY FUNCTION OF THE GLOBULAR-CLUSTER NGC-6752 WITH THE HUBBLE-SPACE-TELESCOPE - EVIDENCE OF MASS SEGREGATION

We present the luminosity function (LF) for the lower main sequence of the Galactic globular cluster NGC 6752, as obtained from Hobble Space Telescope (HST) observations centred 2 arcmin from the cluster centre . We present data in the F814W and F555W filters. Our LF reaches down to M-I= 11 or, translated to a mass function, to M similar or equal to 0.12 M.. The LF reaches a maximum between M-I = 8.5 and 9, and shows no indication of an increase towards lower luminosities/masses; this i s at variance with some ground-based observations, but is similar to a ll other HST-based LFs. There is a clear indication of mass segregatio n since the relative numbers of bright/faint stars differ from that fo und in ground-based observations and in other clusters analysed with t he HST.